Improvement in copying-presses



UNITED STATES PATENT OFFICE.

JOHN FENSOM, OF TORONTO, CANADA.

IMPROVEMENT IN COPYING-PRESSES.

Speoication forming part of Letters Patent No. 116,824, dated July 11,1871.

To all whom t may concern:

Be it known that I, JOHN FENsOM, of the city of Toronto, in the countyof York, Province of Ontario and Dominion of Canada, have inventedcertain Improvements in Copying-Presses for Copying Letters, of whichthe following is a specification':

The invention relates to the application of a ratchet-wheel firmlysecured to the screw or handle Oi' the press, and a spring, made fast inthe handle Or screw, aetin g on the ratchet-wheel, and when more forcethan is necessary is applied to the handle of the press it slips pastthe teeth of the ratchet-wheel, allowing the handle of the press to movewithout increasing Athe pressure on the platen of the press and preventsthe platen being broken by over pressure; or by using a spiral springand bolt in the handle ofthe press the saine effect will be produced.

Figure l represents a side view of a copyingpress embodying myinvention. Fig. '2 represents the handle removed from the press. Figs. 3and 4 show another application of ratchetwheel and spring, which isfully explained in the general description.

Fig. l, A A represent the handle of the press. B represents theratchet-wheel firmly secnred to the screw O of the press. D, a ilatspring made fast in the handle A A. This spring slips past the teeth ofthe ratchet-wheel, allowing the handle of the press to move withoutincreasing the pressure on the platen E; or by using a spiral spring andbolt in the handle, as at d d in Fig. 2, the same e'ect is produced.Fig. 2 represents the handle removed from the press, showing more fullythe arrangements and parts. The same figures and letters apply as inFig. 1. Figs. 3 and 4, A A, the handle, with teeth cnt on the face7acting' in the teeth of the collar B, which is made fast to the screw Oof the press. The handle A A is held in its place by the short spiral,marked d in Fig. 3, which allows the teeth to slip past when too muchforce is applied.

The application of a ratchet-wheel and spring in any form to the screwand handle in copyingpresses, as herein set forth.

JOHN FENSOM.

Titnesses J AMEs TILT, GEORGE DAVIDSON.

